The prognostic value of cyclooxygenase-2 expression in patients with esophageal cancer: evidence from a meta-analysis

Arachidonic acid metabolism as a novel pathogenic factor in gastrointestinal cancers

Gastrointestinal (GI) cancers are a major global health burden, representing 20% of all cancer diagnoses and 22.5% of global cancer-related deaths. Their aggressive nature and resistance to treatment pose a significant challenge, with late-stage survival rates below 15% at five years. Therefore, there is an urgent need to delve deeper into the mechanisms of gastrointestinal cancer progression and optimize treatment strategies. Increasing evidence highlights the active involvement of abnormal arachidonic acid (AA) metabolism in various cancers. AA is a fatty acid mainly metabolized into diverse bioactive compounds by three enzymes: cyclooxygenase, lipoxygenase, and cytochrome P450 enzymes. Abnormal AA metabolism and altered levels of its metabolites may play a pivotal role in the development of GI cancers. However, the underlying mechanisms remain unclear. This review highlights a unique perspective by focusing on the abnormal metabolism of AA and its involvement in GI cancers. We summarize the latest advancements in understanding AA metabolism in GI cancers, outlining changes in AA levels and their potential role in liver, colorectal, pancreatic, esophageal, gastric, and gallbladder cancers. Moreover, we also explore the potential of targeting abnormal AA metabolism for future therapies, considering the current need to explore AA metabolism in GI cancers and outlining promising avenues for further research. Ultimately, such investigations aim to improve treatment options for patients with GI cancers and pave the way for better cancer management in this area.

Mechanistic Insights on Microbiota-Mediated Development and Progression of Esophageal Cancer

Esophageal cancer (EC) is one of the most common malignant tumors worldwide, and its two major types, esophageal adenocarcinoma (EAC) and esophageal squamous cell carcinoma (ESCC), present a severe global public health problem with an increasing incidence and mortality. Established risk factors include smoking, alcohol consumption, and dietary habits, but recent research has highlighted the substantial role of oral microbiota in EC pathogenesis. This review explores the intricate relationship between the microbiome and esophageal carcinogenesis, focusing on the following eight significant mechanisms: chronic inflammation, microbial dysbiosis, production of carcinogenic metabolites, direct interaction with epithelial cells, epigenetic modifications, interaction with gastroesophageal reflux disease (GERD), metabolic changes, and angiogenesis. Certain harmful bacteria, such as Porphyromonas gingivalis and Fusobacterium nucleatum, are specifically implicated in sustaining irritation and tumor progression through pathways including NF-κB and NLRP3 inflammasome. Additionally, the review explores how microbial byproducts, including short-chain fatty acids (SCFAs) and reactive oxygen species (ROS), contribute to DNA harm and disease advancement. Furthermore, the impact of reflux on microbiota composition and its role in esophageal carcinogenesis is evaluated. By combining epidemiological data with mechanistic understanding, this review underscores the potential to target the microbiota-immune system interplay for novel therapeutic and diagnostic strategies to prevent and treat esophageal cancer.

Pathological and pharmacological functions of the metabolites of polyunsaturated fatty acids mediated by cyclooxygenases, lipoxygenases, and cytochrome P450s in cancers

Oxylipins have garnered increasing attention because they were consistently shown to play pathological and/or pharmacological roles in the development of multiple cancers. Oxylipins are the metabolites of polyunsaturated fatty acids via both enzymatic and nonenzymatic pathways. The enzymes mediating the metabolism of PUFAs include but not limited to lipoxygenases (LOXs), cyclooxygenases (COXs), and cytochrome P450s (CYPs) pathways, as well as the down-stream enzymes. Here, we systematically summarized the pleiotropic effects of oxylipins in different cancers through pathological and pharmacological aspects, with specific reference to the enzyme-mediated oxylipins. We discussed the specific roles of oxylipins on cancer onset, growth, invasion, and metastasis, as well as the expression changes in the associated metabolic enzymes and the associated underlying mechanisms. In addition, we also discussed the clinical application and potential of oxylipins and related metabolic enzymes as the targets for cancer prevention and treatment. We found the specific function of most oxylipins in cancers, especially the underlying mechanisms and clinic applications, deserves and needs further investigation. We believe that research on oxylipins will provide not only more therapeutic targets for various cancers but also dietary guidance for both cancer patients and healthy humans.

Targeting inflammation as cancer therapy

Inflammation has accompanied human beings since the emergence of wounds and infections. In the past decades, numerous efforts have been undertaken to explore the potential role of inflammation in cancer, from tumor development, invasion, and metastasis to the resistance of tumors to treatment. Inflammation-targeted agents not only demonstrate the potential to suppress cancer development, but also to improve the efficacy of other therapeutic modalities. In this review, we describe the highly dynamic and complex inflammatory tumor microenvironment, with discussion on key inflammation mediators in cancer including inflammatory cells, inflammatory cytokines, and their downstream intracellular pathways. In addition, we especially address the role of inflammation in cancer development and highlight the action mechanisms of inflammation-targeted therapies in antitumor response. Finally, we summarize the results from both preclinical and clinical studies up to date to illustrate the translation potential of inflammation-targeted therapies.

Blockade of EP4 by ASP7657 Modulates Myeloid Cell Differentiation In Vivo and Enhances the Antitumor Effect of Radiotherapy

The tumor microenvironment (TME) is thought to influence the antitumor efficacy of immuno-oncology agents through various products of both tumor and stromal cells. One immune-suppressive factor is prostaglandin E2 (PGE2), a lipid mediator whose biosynthesis is regulated by ubiquitously expressed cyclooxygenase- (COX-) 1 and inducible COX-2. By activating its receptors, PGE2 induces immune suppression to modulate differentiation of myeloid cells into myeloid-derived suppressor cells (MDSCs) rather than dendritic cells (DCs). Pharmacological blockade of prostaglandin E receptor 4 (EP4) causes a decrease in MDSCs, reprogramming of macrophage polarization, and increase in tumor-infiltrated T cells, leading to enhancement of antitumor immunity in preclinical models. Here, we report the effects of the highly potent EP4 antagonist ASP7657 on the DC population in tumor and antitumor immune activation in an immunocompetent mouse tumor model. Oral administration of ASP7657 inhibited tumor growth, which was accompanied by an increase in intratumor DC and CD8+ T cell populations and a decrease in the M-MDSC population in a CT26 immunocompetent mouse model. The antitumor activity of ASP7657 was dependent on CD8+ T cells and enhanced when combined with an antiprogrammed cell death-1 (PD-1) antibody. Notably, ASP7657 also significantly enhanced the antitumor efficacy of radiotherapy in an anti-PD-1 antibody refractory model. These results indicate that the therapeutic potential of ASP7657 arises via upregulation of DCs and subsequent CD8+ T cell activation in addition to suppression of MDSCs in mouse models and that combining EP4 antagonists with radiotherapy or an anti-PD-1 antibody can improve antitumor efficacy.

Oral Microbiota Variation: A Risk Factor for Development and Poor Prognosis of Esophageal Cancer

Recent studies have shown that oral microbiota play an important role in the esophageal cancer (EC) initiation and progression, suggesting that oral microbiota is a new risk factor for EC. The composition of the microbes inhabiting the oral cavity could be perturbed with continuous factors such as smoking, alcohol consumption, and inflammation. The microbial alteration involves the decrease of beneficial species and the increase of pathogenic species. Experimental evidences suggest a significant role of oral commensal organisms in protecting hosts against EC. By contrast, oral pathogens, especially Porphyromonas gingivalis and Fusobacterium nucleatum, give rise to the risk for developing EC through their pro-inflammatory and pro-tumorigenic activities. The presences of oral dysbiosis, microbial biofilm, and periodontitis in EC patients are found to be associated with invasive cancer phenotypes and poor prognosis. The mechanism of oral bacteria in EC progression is complex, which involves a combination of cytokines, chemokines, oncogenic signaling pathways, cell surface receptors, the degradation of extracellular matrix, and cell apoptosis. From a clinical perspective, good oral hygiene, professional oral care, and rational use of antibiotics bring positive impacts on oral microbial balance, thus helping individuals reduce the risk of EC, inhibiting postoperative complications among EC patients, and improving the efficiency of chemoradiotherapy. However, current oral hygiene practices mainly focus on the oral bacteria-based predictive and preventive purposes. It is still far from implementing microbiota-dependent regulation as a therapy for EC. Further explorations are needed to render oral microbiota a potential target for treating EC.

Effect of taking aspirin before diagnosis on the prognosis of esophageal squamous cell carcinoma and analysis of prognostic factors

Objective

The 5-year survival rate of patients with esophageal squamous cell cancer (ESCC) is very low. However, long-term aspirin use has been suggested to have an adjuvant therapeutic effect. We therefore investigated the effect of long-term aspirin use before ESCC diagnosis on postoperative patient survival.

Methods

We carried out a retrospective cohort study of patients who underwent esophageal cancer resection in our hospital from 2008 to 2018. Patients were divided into an aspirin group (n = 79) and control group (n = 79), and were followed up until December 2019. We analyzed the clinicopathological and follow-up data of the patients during hospitalization, and the cyclooxygenase-2 (COX-2) protein expression levels by immunohistochemistry, and related these to postoperative survival.

Results

Patients who took aspirin had significantly lower survival rates than those who did not. COX-2-negative patients had better survival than patients with either low or high COX-2 expression levels. T stage was the only independent predictor of survival in patients who took aspirin.

Conclusions

Long-term regular use of aspirin before diagnosis had an adverse effect on postoperative survival in patients with ESCC. Different COX-2 protein expression levels were associated with significantly different postoperative survival rates, with COX-2-positive patients having the poorest survival.

Role of prostaglandin E2 in the progression of gastrointestinal cancer

Chronic inflammation is a well-established risk factor for several diseases, including cancer. It influences tumor cell biology and the type and density of immune cells in the tumor microenvironment (TME), promoting cancer development. While pro-inflammatory cytokines and chemokines modulate cancer development, emerging evidence has shown that prostaglandin E2 (PGE2) is a known mediator connecting chronic inflammation to cancerization. This review highlights recent advances in our understanding of how the elevation of PGE2 production promotes gastrointestinal cancer initiation, progression, invasion, metastasis, and recurrence, including modulation of immune checkpoint signaling and the type and density of immune cells in the tumor/tissue microenvironment.

Control of Dendritic Cell Function Within the Tumour Microenvironment

The tumour microenvironment (TME) presents a major block to anti-tumour immune responses and to effective cancer immunotherapy. The inflammatory mediators such as cytokines, chemokines, growth factors and prostaglandins generated in the TME alter the phenotype and function of dendritic cells (DCs) that are critical for a successful adaptive immune response against the growing tumour. In this mini review we discuss how tumour cells and the surrounding stroma modulate DC maturation and trafficking to impact T cell function. Fibroblastic stroma and the associated extracellular matrix around tumours can also provide physical restrictions to infiltrating DCs and other leukocytes. We discuss interactions between the inflammatory TME and infiltrating immune cell function, exploring how the inflammatory TME affects generation of T cell-driven anti-tumour immunity. We discuss the open question of the relative importance of antigen-presentation site; locally within the TME versus tumour-draining lymph nodes. Addressing these questions will potentially increase immune surveillance and enhance anti-tumour immunity.

Network pharmacology reveals potential functional components and underlying molecular mechanisms of Andrographis paniculata in esophageal cancer treatment

Antitumor and antimetastatic effects of the medicinal herb Andrographis paniculata (AP) in esophageal cancer (EC) have been previously reported. In this study, we aimed to uncover the potential functional components and the underlying molecular mechanisms of AP in EC treatment using network pharmacology and experimental validation. Twenty-two potential active AP compounds against EC were revealed, including the antitumor/antiinflammatory compounds panicolin, moslosooflavone, and deoxyandrographiside. Epidermal growth factor receptor (EGFR), signal transducer and activator of transcription 3 (STAT3), RAC-alpha serine/threonine-protein kinase (AKT1), prostaglandin-endoperoxide synthase 2 (PTGS2), chemokine (C-X-C motif) ligand 8 (CXCL8), phosphatidylinositol 4,5-bisphosphate 3-kinase subunit alpha (PIK3CA), and toll-like receptor 4 (TLR4) were most highly ranked among the predicted targets of AP in EC treatment and may play important roles in the anti-EC effects of AP. KEGG pathway analysis revealed the enrichment of multiple cancer-related pathways and signaling pathways. Quantitative reverse transcription-polymerase chain reaction (qRT-PCR) and western blotting validation showed that overnight treatment with 850.3 μg/ml of AP water extract significantly reduced the mRNA expressions of EGFR and AKT in human EC-109 cells. The presence of panicolin and moslosooflavone in the AP water extract samples were confirmed using LC-MS against reference standards. This study has comprehensively revealed for the first time the potential functional components of AP in EC and explored the underlying molecular mechanisms. Future studies should characterize the potential pharmacological properties of the other highly ranked yet understudied compounds in AP detected.

Cyclooxygenases and Prostaglandins in Tumor Immunology and Microenvironment of Gastrointestinal Cancer

Chronic inflammation is a known risk factor for gastrointestinal cancer. The evidence that nonsteroidal anti-inflammatory drugs suppress the incidence, growth, and metastasis of gastrointestinal cancer supports the concept that a nonsteroidal anti-inflammatory drug target, cyclooxygenase, and its downstream bioactive lipid products may provide one of the links between inflammation and cancer. Preclinical studies have demonstrated that the cyclooxygenase-2-prostaglandin E₂ pathway can promote gastrointestinal cancer development. Although the role of this pathway in cancer has been investigated extensively for 2 decades, only recent studies have described its effects on host defenses against transformed epithelial cells. Overcoming tumor-immune evasion remains one of the major challenges in cancer immunotherapy. This review summarizes the impacts of the cyclooxygenase-2-prostaglandin E₂ pathway on gastrointestinal cancer development. Our focus was to highlight recent advances in our understanding of how this pathway induces tumor immune evasion.

The tumour immune microenvironment in oesophageal cancer

Oesophageal cancer (OC) is an inflammation-associated malignancy linked to gastro-oesophageal reflux disease, obesity and tobacco use. Knowledge of the microenvironment of oesophageal tumours is relevant to our understanding of the development of OC and its biology, and has major implications for understanding the response to standard therapies and immunotherapies, as well as for uncovering novel targets. In this context, we discuss what is known about the TME in OC from tumour initiation to development and progression, and how this is relevant to therapy sensitivity and resistance in the two major types of OC. We provide an immunological characterisation of the OC TME and discuss its prognostic implications with specific comparison with the Immunoscore and immune-hot, -cold, altered-immunosuppressed and -altered-excluded models. Targeted therapeutics for the TME under pre-clinical and clinical investigation in OCs are also summarised. A deeper understanding of the TME will enable the development of combination approaches to concurrently target the tumour cells and TME delivering precision medicine to OC patients.

The Role of Microbiota in the Pathogenesis of Esophageal Adenocarcinoma

Simple Summary

Esophageal adenocarcinoma has a poor 5-year survival rate and is among the highest mortality cancers. Changes in the esophageal microbiome have been associated with cancer pathogenesis; however, the molecular mechanism remains obscure. This review article critically analyzes the molecular mechanisms through which microbiota may mediate the development and progression of esophageal adenocarcinoma and its precursors-gastroesophageal reflux disease and Barrett’s esophagus. It summarizes changes in esophageal microbiome composition in normal and pathologic states and subsequently discusses the role of altered microbiota in disease progression. The potential role of esophageal microbiota in protecting against the development of esophageal adenocarcinoma is also discussed. By doing so, this article highlights specific directions for future research developing microbiome-mediated therapeutics for esophageal adenocarcinoma.

Abstract

Esophageal adenocarcinoma (EAC) is associated with poor overall five-year survival. The incidence of esophageal cancer is on the rise, especially in Western societies, and the pathophysiologic mechanisms by which EAC develops are of extreme interest. Several studies have proposed that the esophageal microbiome may play an important role in the pathophysiology of EAC, as well as its precursors—gastroesophageal reflux disease (GERD) and Barrett’s esophagus (BE). Gastrointestinal microbiomes altered by inflammatory states have been shown to mediate tumorigenesis directly and are now being considered as novel targets for both cancer treatment and prevention. Elucidating molecular mechanisms through which the esophageal microbiome potentiates the development of GERD, BE, and EAC will provide a foundation on which new therapeutic targets can be developed. This review summarizes current findings that elucidate the molecular mechanisms by which microbiota promote the pathogenesis of GERD, BE, and EAC, revealing potential directions for additional research on the microbiome-mediated pathophysiology of EAC.

Natural COX-2 Inhibitors as Promising Anti-inflammatory Agents: An Update

COX-2, a key enzyme that catalyzed the rate-limiting steps in the conversion of arachidonic acid to prostaglandins, played a pivotal role in the inflammatory process. Different from other family members, COX-2 was barely detectable in normal physiological conditions and highly inducible during the acute inflammatory response of human bodies to injuries or infections. Therefore, the therapeutic utilization of selective COX-2 inhibitors has already been considered as an effective approach for the treatment of inflammation with diminished side effects. Currently, both traditional and newer NSAIDs are the commonly prescribed medications that treat inflammatory diseases by targeting COX-2. However, due to the cardiovascular side-effects of the NSAIDs, finding reasonable alternatives for these frequently prescribed medicines are a hot spot in medicinal chemistry research. Naturallyoccurring compounds have been reported to inhibit COX-2, thereby possessing beneficial effects against inflammation and certain cell injury. The review mainly concentrated on recently identified natural products and derivatives as COX-2 inhibitors, the characteristics of their structural core scaffolds, their anti-inflammatory effects, molecular mechanisms for enzymatic inhibition, and related structure-activity relationships. According to the structural features, the natural COX-2 inhibitors were mainly divided into the following categories: natural phenols, flavonoids, stilbenes, terpenoids, quinones, and alkaloids. Apart from the anti-inflammatory activities, a few dietary COX-2 inhibitors from nature origin also exhibited chemopreventive effects by targeting COX-2-mediated carcinogenesis. The utilization of these natural remedies in future cancer prevention was also discussed. In all, the survey on the characterized COX-2 inhibitors from natural sources paves the way for the further development of more potent and selective COX-2 inhibitors in the future.

Effect of perioperative flurbiprofen axetil on long-term survival of patients with esophageal carcinoma who underwent thoracoscopic esophagectomy: A retrospective study

Background and Objectives

Nonsteroidal anti‐inflammatory drugs (NSAIDs) have an anti‐inflammatory response, but it remains unclear whether the perioperative use of flurbiprofen axetil can influence postoperative tumor recurrence and survival in esophageal carcinoma. We aimed to explore the effect of perioperative intravenous flurbiprofen axetil on recurrence‐free survival (RFS) and overall survival (OS) in patients with esophageal carcinoma who underwent thoracoscopic esophagectomy.

Methods

This retrospective study included patients who underwent surgery for esophageal carcinoma between December 2009 and May 2015 at the Department of Thoracic Surgery, Anhui Provincial Hospital. Patients were categorized into a non‐NSAIDs group (did not receive flurbiprofen axetil), single‐dose NSAIDs group (received a single dose of flurbiprofen axetil intravenously), and multiple‐dose NSAIDs group (received multiple doses of flurbiprofen).

Results

A total of 847 eligible patients were enrolled. Univariable and multivariable analyses revealed that the intraoperative use of flurbiprofen was associated with long‐term RFS (hazard ratio [HR]: 0.56, 95% confidence interval [CI]: 0.42–0.76, p = .001) and prolonged OS (HR: 0.49, 95% CI: 0.38–0.63, p = .001).

Conclusions

Perioperative flurbiprofen axetil therapy may be associated with prolonged RFS and OS in patients with esophageal carcinoma undergoing thoracoscopic esophagectomy.

Cyclooxygenase-2 Inhibitor: A Potential Combination Strategy With Immunotherapy in Cancer

The clinical application of immunotherapy is the milestone of cancer treatment. However, some patients have bad reaction. Cyclooxygenase-2 (COX-2) is frequently expressed in multiple cancer cells and is associated with poor prognosis. It is the key enzyme of prostaglandin E₂ (PGE2) that has been proved to promote the development, proliferation and metastasis of tumor cells. Recent studies further find the PGE2 in tumor microenvironment (TME) actively triggers tumor immune evasion via many ways, leading to poor response of immunotherapy. COX-2 inhibitor is suggested to restrain the immunosuppression of PGE2 and may enhance or reverse the response of immune checkpoint inhibitors (ICIs). This review provides insight into the mechanism of COX-2/PGE2 signal in immunosuppressive TME and summarizes the clinical application and trials in cancer treatment.

Immunohistochemical detectability of cyclooxygenase-2 expression in cells of human melanocytic skin lesions: A methodological review

Increased cyclooxygenase-2 (COX-2) expression is thought to support tumorigenesis through various mechanisms and is analyzed as a potential cancer marker. In 18 studies, COX-2 expression in melanocytic lesions of human skin was examined immunohistochemically. However, results obtained by individual research groups differ in terms of detection frequency and level of this protein, as well as localization of stained cells within tumor. Possible reasons for the discrepancies are analyzed in this review: the application of different antibodies, the use of standard histopathological sections or tissue microarrays and the analyzes of staining results based on different algorithms. COX-2 level is significantly lower in nevi than in melanomas, increases gradually with progression of these malignant cancers and reaches the highest values in metastases. These gradual changes in COX-2 expression appear to be difficult to analyze based only on subjective assessment of staining intensity. The most convergent data were obtained using antibodies for N-terminal fragments of COX-2 protein and analyzing results based on calculation of percentage fraction of positive cells. The extent of stained area in specimen thus appears to be more important than the intensity of staining in terms of evaluation of COX-2 performance as a diagnostic and prognostic marker of cutaneous melanoma.

Cyclo-oxygenase-2 expression is associated with mean standardised uptake value on 18F-Fluorodeoxyglucose positron emission tomography in oesophageal adenocarcinoma

OBJECTIVES

This pilot study investigated the association of four PET image features and cyclo-oxygenase-2 (COX-2) expression in patients with oesophageal adenocarcinoma. The prognostic significance of these biomarkers was also assessed.

METHODS

50 consecutive patients [median age = 68 (range 47 - 84), males = 45) with oesophageal adenocarcinoma had PET/CT staging between January 2011 and July 2015. The maximum and mean standardised uptake values (SUV_max and SUV_mean), metabolic tumour volume (MTV) and tumour lesion glycolysis (TLG) were calculated from the primary tumour. Their association with COX-2 status was assessed using Mann-Whitney U tests. Kaplan-Meier and Cox regression analysis tested their prognostic significance. A p-value < 0.05 was considered statistically significant.

RESULTS

32 tumours (64.0%) were COX-2 positive. There was a significant association between SUV_mean and COX-2 status (p = 0.019). TLG (hazard ratio (HR) 1.001, 95 % confidence intervals (CI) 1.000 - 1.002, p = 0.018) was significantly associated with overall survival on multivariable analysis.

CONCLUSIONS

This study investigated the association between PET image features and COX-2 expression in oesophageal adenocarcinoma. The preliminary results signal that a combination of TLG (calculated as product of MTV and SUV_mean) and COX-2 status may be a strong and clinically important prognostic biomarker. Our research group are planning a prospective, multi-centre study to validate these findings.

ADVANCES IN KNOWLEDGE

Mean standardised uptake value (SUV_mean) on PET imaging is associated with COX-2 expression in oesophageal adenocarcinoma.

High PTGS2 expression in post-neoadjuvant chemotherapy-treated oesophageal adenocarcinoma is associated with improved survival: a population-based cohort study

AIMS

High prostaglandin endoperoxide synthase-2 (PTGS2) enzyme expression in oesophageal adenocarcinoma has been shown to independently predict poor prognosis; however, the evidence is inconsistent. The aim of this study was to investigated the association between PTGS2 expression and prognosis in patients with oesophageal adenocarcinoma.

METHODS AND RESULTS

A cohort of 135 patients with oesophageal adenocarcinoma who received neoadjuvant chemotherapy and surgery from 2004 to 2012 was identified in the Northern Ireland Cancer Centre. Tissue microarrays were created in the Northern Ireland Biobank, with triplicate cores being sampled from each tumour. Immunohistochemical PTGS2 expression was scored by two independent assessors, with intensity and proportion of tumour staining being used to calculate H-scores for each patient. Cox regression models were used to calculate hazard ratios (HRs) and 95% confidence intervals (CIs) for overall and cancer-specific survival, and recurrence-free survival by PTGS2 expression, with adjustment for potential confounders. Patients were followed up for a mean of 3.0 years (standard deviation 1.8 years). The PTGS2 expression cut-off value was determined from the median H-score of the cohort (270/300). High (n = 79), as compared with low (n = 56), PTGS2 expression was associated with improved cancer-specific survival (adjusted HR 0.56, 95% CI 0.33-0.94; P = 0.03). PTGS2 expression was not significantly associated with recurrence-free survival (adjusted HR 0.85, 95% CI 0.52-1.38; P = 0.51).

CONCLUSIONS

High PTGS2 expression in oesophageal adenocarcinoma tissue was associated with improved overall and cancer-specific survival, in contrast to previous evidence. As this is the first study of its kind to include patients who had undergone neoadjuvant chemotherapy, further studies are needed to clarify these associations.

Prognostic and Clinic-Pathological Significances of SCF and COX-2 Expression in Inflammatory and Malignant Prostatic Lesions

The initiation of prostatic malignancy has been linked to chronic inflammation. Stem cell factor (SCF) is an inflammatory cytokine that is specific to the c-KIT receptor which is type III receptor tyrosine kinase (RTK). Cyclooxygenases (COXs) are the main enzymes which are responsible for prostaglandins production from arachidonic acid. COX2 is an enzyme which is produced under different pathological conditions. The aim of our study; is to investigate the clinicopathological and the prognostic significance of SCF and COX-2 expression in prostatic adenocarcinoma (PC), chronic prostatitis and nodular prostatic hyperplasia (NPH) in a trial to clarify the role of inflammation as a risk factor for prostatic carcinogenesis and cancer progression. SCF and COX-2 tissue protein expression were evaluated in 50 cases of PC, 20 cases of chronic prostatitis and 10 cases of NPH using immunohistochemistry, patients were followed up for 5 years. The relationship between their levels of expressions, clinicopathological, and prognostic criteria were studied. SCF expression in PC was positively correlated with advanced patient age (p = <0.001), high level of PSA (p = 0.010), higher Gleason score (p = 0.011). COX-2 expression in PC was positively correlated with advanced patient age (p = <0.001), high level of PSA (p = 0.016), advanced D'Amico risk group (p = 0.038). High levels of expression of both SCF& COX-2 are associated with higher incidence of tumor relapse, worse disease overall survival and free survival (p < 0.001). SCF and COX-2 are associated with PC progression and associated with poor prognosis in PC patients.

Substrate-inactivated cyclooxygenase-2 is disposed of by exosomes through the ER-Golgi pathway

Catalysis of arachidonic acid (AA) by cyclooxygenase-2 (COX-2) gives rise to a single product that serves as a precursor for all prostaglandins, which are central mediators of inflammation. Rapid up-regulation of COX-2 expression in response to pro-inflammatory stimuli is a well-characterized means of generating the large pool of prostaglandins necessary for inflammation. However, an efficient inflammatory process must also terminate rapidly and thus requires cessation of COX-2 enzymatic activity and removal of excess protein from the cell. Previous studies showed that COX-2 that has not been exposed to AA ('naive') degrades in the cellular proteasome. However, continuous exposure to AA induces suicide inactivation of COX-2 and its elimination no longer occurs in neither the proteasomal nor lysosomal machineries. In the present study, we show that either overexpressed or endogenously induced COX-2 is secreted via exosomes through the endoplasmic reticulum-Golgi pathway. We further find that excretion of COX-2 is significantly enhanced by prolonged exposure to AA. Genetic or chemical inhibition of COX-2 enzymatic activity has no effect on its secretion in the absence of substrate, but prevents the additional activity-dependent secretion. Finally, transfer of COX-2 to target cells only occurs in the absence of AA stimulation. Together, these results suggest that exosomal secretion of AA-activated COX-2 constitutes a means to remove damaged inactive COX-2 from the cell.

COX-2 mediates pro-tumorigenic effects of PKCε in prostate cancer

The pro-oncogenic kinase PKCε is overexpressed in human prostate cancer and cooperates with loss of the tumor suppressor Pten for the development of prostatic adenocarcinoma. However, the effectors driving PKCε-mediated phenotypes remain poorly defined. Here, using cellular and mouse models, we showed that PKCε overexpression acts synergistically with Pten loss to promote NF-κB activation and induce cyclooxygenase-2 (COX-2) expression, phenotypic traits which are also observed in human prostate tumors. Targeted disruption of PKCε from prostate cancer cells impaired COX-2 induction and PGE2 production. Notably, COX-2 inhibitors selectively killed prostate epithelial cells overexpressing PKCε, and this ability was greatly enhanced by Pten loss. Long-term COX-2 inhibition markedly reduced adenocarcinoma formation, as well as angiogenesis in a mouse model of prostate-specific PKCε expression and Pten loss. Overall, our results provide strong evidence for the involvement of the canonical NF-κB pathway and its target gene COX2 as PKCε effectors, and highlight the potential of PKCε as a useful biomarker for the use of COX inhibition for chemopreventive and/or chemotherapeutic purposes in prostate cancer.

Role of prostanoids in gastrointestinal cancer

Chronic inflammation is a risk factor for gastrointestinal cancer and other diseases. Most studies have focused on cytokines and chemokines as mediators connecting chronic inflammation to cancer, whereas the involvement of lipid mediators, including prostanoids, has not been extensively investigated. Prostanoids are among the earliest signaling molecules released in response to inflammation. Multiple lines of evidence suggest that prostanoids are involved in gastrointestinal cancer. In this Review, we discuss how prostanoids impact gastrointestinal cancer development. In particular, we highlight recent advances in our understanding of how prostaglandin E2 induces the immunosuppressive microenvironment in gastrointestinal cancers.

COX-2 as a determinant of lower disease-free survival for patients affected by ameloblastoma

Ameloblastoma is a locally aggressive neoplasm with a poorly understood pathogenesis. Therefore, the aim of this study is to investigate whether COX-2 expression is associated with ameloblastoma microvascular density (MVD) and with tumor aggressiveness. Sixty-three cases of primary ameloblastomas arranged in tissue microarray were submitted to immunohistochemistry against cyclooxigenase-2 (COX-2) and CD34. Clinicopathological parameters regarding sex, age, tumour size, tumour duration, tumour location, treatment, recurrences, radiographic features, vestibular/lingual and basal cortical disruption and follow-up data were obtained from patients' medical records and correlated with the proteins expression. The results on BRAF-V600E expression were obtained from our previous study and correlated with COX-2 and CD34 expressions. Log-rank univariate analysis and multivariate Cox regression model were done to investigate the prognostic potential of the molecular markers. Twenty-eight cases (44.4%) exhibited cytoplasmic positivity for COX-2, predominantly in the columnar peripheral cells, with a mean MVD of 2.2 vessels/mm². COX-2 was significantly associated with recurrences (p < 0.001) and BRAF-V600E expression (p < 0.001), whereas lower MVD was associated with the use of conservative therapy (p = 0.004). Using univariate and multivariate analyses, COX-2 was significantly associated with a lower 5-year disease-free survival (DFS) rate (p < 0.001 and p = 0.012, respectively), but not with a higher MVD (p = 0.68). In conclusion, COX-2 expression in ameloblastomas is not associated with MVD, but it is significantly associated with recurrences and with a lower DFS.